Electrotherapeutic machine



June 1930- H. P. PULLWITT 1,764,347

ELECTROTHERAPEUT IC MACHINE Filed Oct. 26, 1928- 6 Sheets-Sheet 1 INVENTOR HERMAN P PULLVV/TT A TTORNEY.

June 17, 1930. H. P. PULLWITT ELECTROTHERAPEUTIC MACHINE Filed 001:. 26, 1928 6 Sheets-Sheet 2 mw 0/ M M m H i/IZMMZZ m A T TORNE Y.

June 17, 1930. H. P. PULLWITT 1,764,347

ELECTROTHERAPEUTIC MACHINE Filed Oct. 26, 1928 6 Sheets-Sheet 3 I N VEN TOR HEEMANF Pa; 1. W/Tr A TTORNEY.

Jun 17, 193 H. P. PULLWITT 1,764,347

ELECTROTHERAPEUTI C MACH INE Filed Oct. 2a, 1928 6 Sheets-$heet 4 INVENTOR HEP/VAN P. PULL W/77.

BYMMT ('3. m

A TTORNE Y.

June 17, 1930. 7 v H. P. PULLWITT 4 ELECTROTHERAPEUTIC MACHINE I INVENT HERMAN P PULLW/ A TTORNE Y.

1o generatin Patented June 17, 1930 UNITED STATES PATENT OFFICE HERMAN P. PULLWITT, 01' OAK PARK, ILLINOIS, ASSIGNOB TO HCINTOSE ELECTRICAL CORPORATION, OF CHICAGO, ILLINOIS, A CORPORATION 01 DELAWARE ELECTBOTHEBAPEUTIC MACHINE Application filed October 26, 1928. Serial No. 815,189.

patients circuit, various modalities of elec-- tric current, for examplegalvanic current, 5 slow sinusoidal current, rapid sinusoidal current and combinations of the same, de-

pending upon the stimulating and tonic efi'ect desired.

' In my machine I provide devices for direct current and alternating current, evices for producing slow sinusoidal current, devices for changing the frequency of the slow sinusoidal current as desired, switching mechanism for selectively 15 connecting the circuits of the machine to .communicate direct or galvanic current, alternating current, slow sinusoidal current of a desired frequency, or a combination of these current modalities to the patients cir- 20 cuit as desired, and in addition, voltage regulating devices to control the voltage of the current delivered to the atients circuit, whatever its modality may e.

By my invention, the slow sinusoidal current roduced, has a true sine wave form, and tiie periodicity or frequency may readily be made from 10 to 12 cycles per minute, or lower if desired, and from that value upwards to 100, cycles per minute, or hlgher if desired, by simply turning the frequency controlling knob of the machine, maintaining at all times a true sine wave form of delivered current waves, regardless of how rapid or how slow the frequency my be.

In some cases of impaired muse ar tone, it is found desirable to vigorously exercise the muscles involved by the application oi slow sinusoidal'current, and at the same time afford brief intervals of rest between contractions to avoid'fatigue. This I'provide for in my machine, by furnishing certain of the current modalities selectively delivered, with waves of true sine form and of slow frequency, separated by intervals of no current flow, constituting interrupted slow sinusoidal current modalities.

Again, in other cases of muscular degeneration, it is found to be beneficial to hold the muscular fibres under tension briefly, during each contraction produced by the treatment applied. This I provide for in my machine, by furnishing certain of the current modalities delivered, with waves of true sine form and of slow frequency, each of which waves has a continuing maximum or peak value for an interval equal to that for which the tension on the muscular fibres is to be maintained. These constitute slow sinusoidal sustained peak current modalities.

In producing slow sinusoidal current by my machine, employ a form of current wave producing mechanism, to which de-' sired current, whether galvanic, alternatin or a combination of the two may be applied, and from which by suitable brushes, current in the form of slow sinusoidal current is delivered, without the use of electro-magnetic induction in any way, means being provided in connection with the wave producin mech anism to impart a desired speed 0 movement to the brushes, resulting in a corresponding frequency of the slow sinusoidal current. In this way the characteristics of the current applied to the wave producing mechanism, are faithfully preserved and are delivered from the wave producing mechanism with the same characteristics, excepting that the delivered current as a whole has the additional characteristic of having a wave form of slow periodicity, to which slow wave current I prefer to impart a true sine wave form, thus permitting the delivery to a patients circuit of slow sinusoidal current. This part of my machine affords a convenient means for im arting sinusoidal characteristics to any Form of electric current supplied to the wave producing mechanism.

By my invention I provide im roved means for interrupting cyclic current 50w, whether galvanic, alternating, slow sinusoidal, or a combination of these current modalities, so that a period of no current flow occurs between successive intervals of current flow, by

ever, conductively opening the circuits involved in delivering the interrupted cyclic current from the wave producing mechanism. In connection with this part of my in vention, I may employ in my wave producing mechanism a part having uniform movement which may be selectively operated at different rates as desired corresponding to the periodicity or frequency of the slow wave current to be delivered from the mechanism, and an electric conductor having the current applied to the mechanism, flowing through it and producing in it a drop of electrical potential distributed throughout the length of the conductor, with which conductor the movable part is in contact to engage successively different parts of the conductor producing a cyclic potential diiference between the movable part and each end of the conductor, together with devices selectively establishing a zone of constant electrical potential at one end portion of the conductor in the path of travel of the movable part. In this case, the interrupted cyclic action is secured by maintaining the movable part in electrical connection with the part of the conductor having constant potential,'without however, interrupting movement of the movable part, for periods corresponding with the desired periods of interruption, and delivering wave current by using the constant potential portion of the conductor and the movable part as the supply terminals of the delivery circuit.

' In other cases, I may employ two parts movable on the conductor, in which event the interruption in the cyclic action referred to, is effected by maintaining the two movable parts at the same electrical potential without interrupting their movement for periods corresponding with the periods of interruption of the cyclic action, and using the two movable parts as supply terminals of the delivery circuit.

By my invention I further provide devices in connection with the wave producing mechanism, by which the maximum electrical potential applied to a part moving on a conductor as described, and communicated to the output circuit of the mechanism, may be maintained at maximum value for desired intervals corresponding with the peak values of the cyclic action of the mechanism, and that where two movable parts are used to control current flow to the output circuit, the maximum potential between these parts and impressed upon them by the wave producing mechanism. is maintained for a desired period at each peak of the cyclic action of the mechanism. and furthermore that this sustained maximum potential condition upon the output circuit may be secured for any par ticular current modality supplied to the wave producing mechanism whether galvanic, alternating, slow sinusoidal, or a combination of these modalities, and.I designate, for

convenience, any current modality having its peak values thus maintained for appreciable intervals as a sustained peak current modality.

More specifically, the wave producing mechanism employed in my machine, may consist of a resistance winding to the terminals of which the current modality may be applied, to which cyclic effect is to be given, the resistance winding being disposed in such a manner that a brush or brushes may rotate over it and be subjected to the potential or potential differences of or between the points of contact with the resistance winding, as the case may be. This, it will be observed, involves no magnetic induction, and yet provides a convenient and simple means for producing cyclic current flow, for example slow sinusoidal current flow, whatever may be the form of the current modality sup;

plied to the resistance winding, as a result of which the delivered sinusoidal current may in addition to being sinusoidal as to its resultant current value, he at the same time galvanic, alternating or a combination of the two. With this construction, interrupted current modalities result from the selective use of devices maintaining the brush or brushes in zones of zero potential or differences of potential for periods corresponding to the periods of cyclic interruption, without however, interrupting the electrical circuits or stopping the rotation of the brushes on the resistance wire, and sustained peak current modalities result from subjecting the brush or brushes to maximum potential for periods corresponding to the periods of maximum voltage of the cyclic current delivered from the wave producing mechanism, without modifying the rotation of the brushes or opening any of the circuit connections.

By my invention I provide a novel switching mechanism in the form of an unitary device having a single operating knob or handle, by which galvanic or alternating current, or a combination of the two may be selectively applied to the wave producing mechanism, and by which the interrupting devices and the sustained peak devices may be selectively connected for operation as desired. The result is that a multiplicity of current modalities may be selectively impressed upon the patients circuit, by the operation of the single switch knob, depending upon the particular nature of treatment desired.

By my invention I further provide novel means for controlling the rate of operation of the wave producing mechanism, to the end that the cyclic current, for example slow sinusoidal current, whatever the characteris tics of its wave may be, may have a desired rate or frequency of operation.

By my invention I also provide as a part of my improved machine, a rheostat, actuated by a suitable controlling knob or handle, for changing as desired the voltage of the particular current modality delivered to the patients circuit, and in this way I completely control the output of my machine as to current modality selected, the frequency of the slow cyclic or sinusoidal current delivered, and the voltage of the current, by three adjusting knobs.

By my invention I also provide my machine with a pilot lamp connected in a manner to be subjected to the electrical potential available at any time for the patient s circuit, whereby this lamp affords an indication'to the operator of whether the machine is in operation, and also affords an indication of the kind of current delivered to the patients circuit, and of the frequency and nature ofthe slow sinusoidal current, when that modality in its several aspects, is employed.

In carrying out my invention, I referably mount the controlling and indicating devices above and on a panel constituting the top of a cabinet, and the apparatus controlled by the controlling devices is preferably mounted from the lower surface of this panel to constitute a self contained structure, which results in the only apparatus above the panel being the controlling and indicating apparatus and in having all of the electrical parts and connections, excepting the binding posts of the patients circuit, located below the panel where they are protected and concealed from view. In this manner, the moving parts of the apparatus and all of the electrical connections when assembled and made, are in permanent relation to each other and the possibility of proper operative relation between the parts being disturbed, is reduced to a minimum, and furthermore, when inspection of the apparatus is necessaryit can be simply effected by raising the panel and placing it in any convenient position or location, which does not disturb the relation of the electrical connections and operating parts, leaving them operative at all times and permitting convenient inspection and repair when necessary.

The above and other objects of my invention will best be understood by reference to the accompanying drawings showing a preferred embodiment thereof, in which Fig. 1 is a perspective view of the top panel and front of my complete machine,

Fig. 2 is a top view of the panel of my machine, to an enlarged scale,

Fig. 3 is a back view showing the upper part of my machine in elevation, and the stand in vertical, sectional view,

Fig. 4 is a bottom view of a pad heater that may be conveniently used with my machine,

Fig. 5 is a bottom view of the panel shown in Fig. 2, illustrating the mechanism supported by the panel below it,

Fig. 6 is a vertical, sectionalview to an enlarged scale, of the parts shownin Fig. 5 taken along the line 66,

Fig. 7 is a sectional view of a part of the construction shown in Fig. 6, taken along the line 7-7,

Fig. 8 is a top view of the resistance element of the wave producingmechanism,

Fig. 9 is a sectional view to an enlarged scale of some of the parts shown in Fig. 5, taken along the line 99,

Fig. 10 is a sectional view of the parts shown in Fig. 2, taken along the line 1U--10,

Fig. 11 is a diagrammatic circuit diagram of the wiring of the machine, and

Figs. 12-27 inclusive are diagrammatic views of the current wave forms of the various current modalities which may be delivered selectively to the patients circuit by the machine.

Similar numerals refer to similar parts throughout the several views.

As shown in Fig. 1, my machine consists of a panel 10, carrying the controlling and indicating devices above it and supporting the apparatus of the machine below it in a manner to be described, this panel being supported by a stand 11, provided with handle rods 12 and 13 for moving it conveniently from place to place on the castors 14 of the machine. As more clearly shown in Fig. 2, the panel 10 carries a line switch 15 for starting and stopping themachine, a pole changing switch 16 for determining the direction of galvanic current flow through the binding posts 17 and 18 of the patients circuit which are also supported by the panel, a first knob 19 for o crating the current modality switch to supp y a desired current modality to the binding posts 17 and 18, a second knob 20 for chan ing as desired the volt-age of the current elivered to the posts 17 and 18, a third knob 21 for changing the frequency of the slow sinusoidal current selectively delivered to the posts 17 and 18, a pilot lamp 22 and a milliammeter 23 for indicating the amount of current flowing in the patients circuit.

As shown in Fig. 3, the rear wall 24 of a casing supported by the stand 11 and carrying the panel 10, is provided with afirst electrical socket 25 for convenient connection with electric wires for supplying the machine with current, for example from the usual lighting circuit, and a second electrical socket 26 of the receptacle type, to receive a plug 27 connected by flexible electrical conductors 28 with an electric heater, for example a pad heating device 29. It will be noted that the handle rods 12 and 13 are substantially parallel with the sides of the stand and that, as shown in Fig. 3, the upper frame members of the stand are metal tubes 11, 11 comprising ledges from which metal sheets 11*, 11 extend downwardly to form the side walls of the stand. The heater 29 is provided with downwardly extending short posts or lu 30 resting against the inner surface of t e handle rod 12, for the relation of the parts shown in Fig. 3, and the inner edge of the heater 29, on its lower surface, is provided with lugs 31 pro 'ecting sulficiently to extend under the a jacent tube 11, nearly or quite into contact with the corresponding metal sheet 11", as a result of which the heater 29 is securely supported on the handle rod 12 and with such rigidity that the heater itself may be used to roll the stand and machine from one location to another. The heater may conveniently be provided with an electric switch or switches 32 to control current flow through it. WVhenit is desired to remove the heater from the machine all that is required is to remove the plug 27 from the socket 26 and to raise the outer edge of the heater sufliciently to clear the posts 30 from the handle rod 12 which completely frees the heater from the machine. The heater can be quite as readily placed on the machine by a reverse operation. A second similar heater 29 is shown supported by the handle rod 13 and in the same manner, to illustrate that a heater of the kind under consideration may readily be supported by the machine on either of its handle rods 12 and 13.

As shown in Fig. 5, the panel 10 carries from its under surface, a motor generator consisting of two units 33 and 34, substantially in alignment with each other and having shafts connected by a coupling device 35 so that rotation of one of the shafts rotates the other of the shafts. One of the shafts, for example the shaft 36 of the unit 34 carries a worm 37 meshing with a worm wheel 38, supported in a manner to be described, by a metal housing 39 supported by the panel 10, to drive the movable parts of the apparatus. The unit 33 of the motor generator is a motor designed to be driven by electric current that may be available. The unit 34 is an electric generator having direct current output conductors 110 and 111, which may be respectively positive and negative, and having also alternating current output conductors 111 and 112. The conductors 111 and 111", as shown, are both connected electrically with conductor 111, which, together with the conductors 110 and 112, constitute the supply conductors extending to the electrical circuits of my machine. The genera- A tor 34 is preferably designed to deliver rapidly alternating current, for example of afrequency of 60 cycles per second, or higher,

as desired. Since the particular construction of the motor 33 and generator 34, constitutes no part of the present invention, and embodies only structures well known in the art, no particular description of this part of the apparatus is thought to be required.

Besides the parts referred to, the panel 10 carries from its under side, as shown in Fig. 5, amain switch block M and an auxiliary switch block A, co-operating with switches in a manner to be described, to constitute a single switching means for connecting the circuits of the machine to selectively communicate to the patients circuit, any desired current modality which the machine is-capable of delivering. The panel 10 similarly supports a rheostat 40 below which an elecsurface, bars 42 and 43 of insulating material carrying at their ends, plunger contacts 44 and 45 extending upwardly through a central circular aperture 46 in the panel 10, for a purpose to be described.

As shown in. Fig. 6, the housing 39 supports a shaft 47 in suitable hearings, in inclined position to carry the worm wheel 38 so that it meshes with and is driven by the worm 37. The upper face of the worm wheel 38 carries a friction cone 48, the conical surface of which is in contact with the periphery of a friction wheel 49 carried by a hub 50 slidable longitudinally on a shaft 51, supported in suitable bearings by the housing 39, at an angle with the shaft 47 corresponding with the angle of the cone 48, so that as the wheel 49 moves longitudinally on the shaft 51 to secure different speed adjustments of the apparatus, its periphery is at all times in frictional engagement with the surface of the cone 48, to drive the apparatus operated by the shaft 51. The shaft 51 is provided with a keyway 52 engaged by the end of a set screw 53 extending through the hub 50, so that angular motion of the hub 50 and the wheel 49 on the shaft 51 is prevented, but free longitudinal movement of the hub and wheel on the shaft is permitted. The hub 50 is provided with an upper extension 54 engaging one member 55 of a ball bearing,

the other member 56 of which is carried b a ring 57. As shown in Fig. 7, the ring 57 carries a screw 58 extending radially therefrom through the end of an adjusting arm 59, which arm is pivotally supported by the housing 39 for rotation around a stud 60', as shown in Fig. .6. The arm 59 is integral with a segmental portion 61 extending upwardly from the pivotal portion of the arm 59, to carry a segmental, gear 62 meshing with an idler gear 63, which latter in turn meshes with a gear 64' secured to the lower end of The panel 10 also supports from its under an operating rod 65, supported in a suitable hearing by the housing 39, to extend upwardly through the panel 10. The upper end of the rod 65 carries a tubular and slotted connecting sleeve 66, for receiving the lower end of the rod 67 extending downwardly from the operating knob 21, as shown in Fig. 10. As a result of the construction just described, rotation of the knob 21 moves the arm 59 on its pivot rod 60, and thus moves the friction wheel 49 longitudinally on the shaft 51 to impart diilerent rates of rotation to the shaft 51, assumin that the motor shaft 36 is driven at a uni orm speed, which is usually the case.

The shaft 51, as shown in Fig. 6, is extended a short distance above the uppermost position of the ring 57 and rigidly carries an upwardly extending tubular shaft 51*, coaxial with the shaft 51. The tubular shaft 51" has mounted upon its upper end, in the opening 46 in the panel 10, oppositely extending radial arms 68 and 69, carrying at their outer ends brushes and 71 of the plunger type which bear against the under surface of a resistance block 7 2, which block for convenience and to distinguish it from other parts of the apparatus, I call the rotor block. As a result of the construction described, the rotation of the shaft 51 rotates the brushes 70 and 71 on the rotor block, and since the brushes are at the same radial distance from the axis of the shaft, each brush has the same path of travel on the rotor block as the other.

The arms 68 and 69 also carry auxiliary brushes 73 and 7 4 supported by springs 7 5 and 76 electrically connecting them with brushes 70 and 71 respectively, which brushes 73 and 74; extend downwardly through the arms 68 and 69, to engage contact segments 77 and-78 carried by the upper surface of the housin 39. It will be understood that all of the brushes 7 0, 71, 7 3 and 74, as well as the contact segments 77 and 78, are electrically insulated from the parts carrying them.

The tubular shaft 51 also carries two collector rings 79 and 80, which are insulated from the shaft and from each other, and have resting upon them plunger brushes 81 and 82 respectively, carried by and insulated from the housing 39. Wires 83 and 84 extend through the tubular shaft 51, connecting the brushes 70 and 71 with the collector rings 79 and respectively. The tubular shaft 51 also carries adjacent the collector rings 79 and 80, an interrupter commutator 85, upon 1 which oppositely disposed brushes 86 and 87 rest. The brushes 86 and 87 are of the plunger type, and are carried by and insulated from the housing 39 and from each other, and comprise a means for interrupting current flow through any circuit connected with these brushes, by periodically opening the circuit. The brushes 81 and 82 comprise a means for impressing upon any desired circuit the trical potential of either or both of brushes 70 and 71 as desired.

In Fig. 8, I show the rotor block 79 top view. This block comprises a fist h i, of insulating material, upon which ance Wire 7 2* is closely wound and counec at its ends with terminals 88 and my connecting any desired source of current with the terminals 88 and 89, current will be caused to flow through the rotor winding 72", the drop'in voltage through the windingbe determined by the voltage impressedupon it from the source of current, and the resulting current flow through the winding As a result, when the brushes 7 O and 71 are rotated as described, the difference of electrical po tential between them for the position sho n in Fig. 8 will be zero, since both rest upon the same wire of the winding 72", and the brushes are moved augularly from the posi tion shown, the difference of potential between them increases until when they are a position at right angles to that shot a, the potential difference between them is a maximum, and in this way, by uniformly tating the brushes, the difference oat electrical potential between them may be given wave form that is a true sine wave, direct current to be flowing through the ing 7 2* from a source of electromoti've It will also be observed, that the ditfere electrical potential between either o brushes 7 O and 71, and either of the t 88 and 89 of the winding 72, will v minimum to maximum and then minimum, for each rotation "of th and that this variation will have that is a true sine wave for t T" of the brushes, and direct on? stant potential through the W'll'ldillg?" will be observed however, that the sin potential difference between; 1 and 71 resulting from their uni-for is alternating in character, for each current wave delivered by them, is an bv a reversed, or negative curre whereas the potential diri'e i either brush and either winding 'tei an unidirectional, and all or the curren' resulting from such potential ditto be sinusoidal and either all not negative. depending upon which it the winding 72", is connected w to which current is delivered. will served that by selecting a path of the brushes 70 and 71, having equal to the transverse width oi 72 the maximum potential din tween the brushes 70 and 71 is equ, tiallv to the voltage drop through th ing 72", and that the maximum potentis ference between either brush and e minal of the winding 72 is substanti, also to said voltage'drop.

The plunger contacts 44 and 45 bear upon the lower surface of the winding 72 at points substantially equidistant from the ends of the winding, and as a result, when these contacts 44 and 45 are connected respectively with the terminals 88 and 89 of the winding 7 2 the full voltage drop through the winding is absorbed by that part of the winding between the contacts 44 and 45; under such conditions, for rotation of the brushes and 71 as above described, the difference of potential between the brushes 70 and 71, increases until the brushes engage the parts of the winding connected with the contacts 44 and 45, and during the intervals that the brushes are traveling over the parts of the winding that are short circui'ted by the contacts 44 and 45 when so connected, this maximum difference of potential is maintained and the characteristic above referred to as sustained peak, results. The se mental contacts 77 and 78 are preferably disposed angularly so that when these contacts are electrically connected with the terminals 88 and 89 respectively, a similar short circuiting of the end portions of the winding 72", to that described by connecting the contacts 44 and 45 with the terminals 88 and 89, results and with similar eifect. Provision is made for connecting the contacts 44 and 45 and the segmental contacts 77 and 78 as desired, in a manner to be described, so that not only the results already particularly described may be secured, at other desirable results in connection with different modalities of the current desired to be communicated to the patients circuit. a

The relation of one of the plunger contacts 44 and 45, for example the contact 44, to the winding 72 is more clearly shown in Fig. 9.

As shown in Fig. 10, the rheostat 40, which is wound with resistance wire 41 and provided with terminals in a manner similar to the rotor block 72 above described, is mounted below the knob 20 and engaged by a contact arm 90, carried by the lower end of an o crating rod 92, extending downwardly rom the knob 20. A stationar contact clip 93 is provided which is in e ectrical contact with the arm 90, and any part of the resistance of the wirin of the rotor block may be included in a desired circuit by connecting one terminal of the winding and the contact clip 93 in said circuit.

As indicated in Fig. 10, the main switch block M is provided with four concentric rows of switch contacts, engaged by switch blades 94, 95, 96 and 97, which are carried by a rod 98 extending downwardly from the control knob 19, said switch blades being insulated from each other and from the rod 98. Each of the switch blades 94, 95, 96 and 97 is provided with downwardly extending ends for selectively connecting the contacts of the main switch block M as follows: The

switch blade 94 connects a selected contact in the outer row with a contact in the same row that is diametrically opposite to the first contact; the switch blade 95 similarly connects diametrically op osite contacts in the second row; the switch blade 96 similarly connects diametrically opposite contacts in the third row, and the switch blade 97 similarly connects diametrically opposite contacts of the fourth or inner row of contacts. The rod 98 besides su porting the switch blades 94, 95, 96 and 9?, also carries below the auxiliary switch block A, oppositely extending metal arms 99 and 100, which are insulated from each other and from the rod 98 and are in the plane of the switch blades 94, 95, 96 and 97. The auxiliary switch block A carries six concentric rows of contacts, the contacts of the outer three rows being respectively and selectively engaged by the plunger contacts 101, 102 and 103 carried by the arm 100, so that any position of the kno 19 bringing the arm 100 in line radially with two or three contacts in the three outer rows of contacts, results in electrically connecting the contacts which are in line with the arm 100 at that time. Similarly, the arm 99 carries three plunger contacts 104, 105 and 106 for selectively engaging respectively the contacts of the three inner rows carried by the auxiliary switch block A, and these plunger contacts electrically connect any of the contacts of the three inner rows that may be in line radially with the arm 99 for any particular adjustment of the knob 19, the plunger contact 101 enga ing the outermost row of the contacts and t e plunger contact 106 engaging the innermost row of the contacts of the auxiliary switch block.

Current modalities My machine above described, as illustrating my present invention, provides for delivering to the posts 17 and 18 of the patients circuit, sixteen different current modalities, that is to say electric currents having sixteen different characteristics, each applicable to a particular treatment of the patient, and for convenience in reference, I refer to these current modalities in terms employed in the electro-therapy, to conveniently identify them and distinguish them from each other.

In Figs. 12-27 inclusive, I illustrate dia grammatically the wave forms of the different current modalities which my machine is adapted to deliver, as illustrative of my invention.

Fig. 12 illustrates galvanic current, which is a current of substantially constant value resulting from the application to the patients circuit of constant electromot-ive force.

Fig. 13 illustrates uni-directional galvanic wave current, and comprises a succession of current waves of the same electrical sign and rent is illustrated, resultin from supplying the winding of the rotor block 72 with direct current, and impressing the potential difference between the brushes and 71 on the posts 17 and 18. r.

In Fig. 15, alternating sinusoidal wave current is illustrated, resulting from supplying the rotor winding with alternating current, and impressing upon the posts 17 and 18 the potential di erences between the brushes 70 and 71. It will be noted that the alternations of current delivered by the generator 34, are present and with the same frequency as found in the alternatin current output circuit of the generator, the difference being that the voltage of theysuccessive alternating current waves constituting any one of the sinusoidal waves, varies substantially as indicated for slow galvanic sinusoidalcurrent, excepting that on account of the alternatin nature of the current impressed upon the winding of the rotor block, the sinusoidal waves are symmetrical about the reference axis, instead of being alternately positive and negative, as illustrated for the slow galvanic sinusoidal current.

In Fig. 1.6, superimposed wave current is illustrated resulting from impressing upon the winding of the rotor block 72, a combination of direct and alternating current and impressing upon the posts 17 and 18, the potential difference between the brushes 70 and 71. This effect is similar to slow alvanic sinusoidal current, the difierence being that each wave consists of alternations of the same frequency as the frequency of the alternating current enerated, the sinusoidal waves resulting rom variations in the voltages of the alternations, due to'impressin upon the posts 17 and 18, the potential di erence between the brushes 7 O and 71.

In Fig. 17, alternating sinusoidal inter .rupted current is illustrated, which is similar to' the current modality illustrated in Fig. 15, excepting thatbetween successive groups of alternations, each of which as a whole is sinusoidal in form, a period of interruption occurs, due to connecting together the plun er contacts 44 and 45., as a result of whicli, for periods corresponding with those during which the brushes 70 and 71 pass over the portion of the winding 72 between the plunger contacts 44 and 45, no electrical potential is impressed upon the posts 17 and 18.

In Fig. 18, slow sinusoidal interrupted current is illustrated, which is generally similar to the current modality illustrated in Fig. 14,

excepting that between successive sinusoidal waves, a period of no current fiow exists, due

to connecting the plunger contacts 44 and 45 in the manner referred to in connection with the current modality illustrated in Fig. 17 and with the same results.

In Fig. 19, interrupted galvanic wave current is illustrated, which is'similar to the current modality illustrated in Fig. 13, excepting that between successive sinusoidal waves. a period of no current flow exists, resulting from connecting one of the plunger contacts 44 and 45, with one of the terminals of the rotor winding, and impressing upon the posts 17 and 18, the otential difference beteween that terminal of the winding and one of the brushes 70 and 71.

In Fig. 20, rapid sinusoidal current is illustrated, which is the result of supplying to the posts- 17 and 18, alternating current from the generator 34.

In Fig. 21, interrupted rapid sinusoidal current is illustrated, which is the result of inserting in the circuit used with the current modality illustrated in Fig. 20, the interrupter 85, thus producing in a manner to be described, periods of no current flow between successive periods of rapid sinusoidal current flow.

In Fig. 22, combined galvanic and sinus oidal current is illustrated, due to impressing on the posts 17 and 18 the combined'voltage of the alternating current and direct current output conductors of the generator 34, the direct current voltage being substantially equal to the alternating current voltage, as a result of which, the rapid sinusoidal waves are all of the same polarity.

In Fig. 23, interrupted galvanic current is illustrated, resulting from inserting in the circuit used in producing the current modality illustrated in Fig. 12, the interrupter 85, which interrupts the current flow periodically, in a manner to be described. I

In Fig. 24, galvanic wave sustained peak current is illustrated, which is similar to the current modality illustrated in Fig. 13, excepting that each current wave is of substantially the same maximum value for an ap preciable interval, instead of having an in stantaneous peak value, as is the case with the current modality shown in Fig. 13. The current modality illustrated in Fig. 24, results from connecting one of the plunger contacts 44 and 45 and the corresponding segmental contact 77 or 78, with one terminal of the rotor winding, connecting that terminal with one of the direct current output con-- ductors of the generator 34, and impressing upon the posts 17 and 1 8 the potential difference between one of the brushes 70 and 71. and the other direct current output conductor of the generator. As pointed out above, the connecting of the plunger contact and the segmental contact with the terminal of the rotor winding, impresses a constant electrical potential upon the rotor brush connected in circuit, while it is passing over the short circuited section of the winding of the rotor block, and while the corresponding auxiliary rotor brush is in engagement with the segmental contact. IVith the circuit connections referred to, this occurs at the time of miximum potential difference between the brush 70 or 71, as the case may be, and the direct current output conductor of the generator, which is directly connected with one of the posts 17 and 18, and thus for an appreciable interval for each wave of the galvanic wave current, the current flow is of constant and maximum amount, as illustrated diagrammatically in Fig. 24.

In Fig. 25, slow galvanic sinusoidal sustained peak current is illustrated, which is similar to the current modality illustrated in Fig. 14, excepting that the current is of constant maximum value for an appreciable interval at the peak of each wave of each sign, instead of having an instantaneous maximum value, as illustrated in Fig. 14.. This result is secured by causing direct current flow through the winding of the rotor block, and connecting each terminal of the winding with the adjacent one of the plunger contacts 44 and 45, and with the adjacent one of the segmental contacts 77 and 78, and impressing upon the posts 17 and 18, the potential difterence between the rotor brushes 70 and 71.

- As above described, the maximum potential difference between the brushes 'FOand 71. exists at the time when they enter the short circuited end zones of the winding of the rotor block, and this maximum potential dif-= l erence is maintained. during each entire period that the brushes and 71 engage the short circuited end portions of the said winding, during each of which periods. the voltage impressed upon the posts 17 and 18 is substantially constant, the successive waves being positive and negative. as and for the reasons described in connection with Fig. 8 above.

In Fig. 26, alternating sinusoidal sustained peak current is illustrated. which is similar to the current modality illustrated in Fig. 15, excepting that the maximum current value of each group of current alternations is substantially constant for an appreciable intcrval, instead of having an instantaneous peak value as illustrated in Fig. 15. This result is secured by connecting the plunger contacts and the segmental contacts in the manner described in connection with Fig. and supplying to the winding of the rotor block alternating current instead of direct current. and connecting the brushes 70 and 71 with the posts 17 and 18 in the same manner they are connected for the current modality illustrated in Fig. 25.

In Fig. 27, superimposed wave sustained peak current is illustrated, which is similar to the current modality illustrated in Fig. 16, excepting that the plunger contacts 44 and 45 and the corresponding segmental contacts 77 and 78, are connected with the adjacent terminals of the winding of the rotor block, as described for the current modality illustrated in Fig. 25. This results in each group of current alternations having a constant maximum value for an appreciable interval, instead of an instantaneous peak value, as is the case for the current modality illustrated in F igt.) 16. In this case the winding of the rotor lock is supplied with current of the kind and in the same manner as described in connection with Fig. 16, with the result that the alternations and waves are sinusoidal in character.

It will be understood that in connection with each of the current modalities illustrated, the rheostat 40 is connected in circuit, so that by operation of the arm 90 by the knob 20, the voltage impressed upon the posts 17 and 18 may be varied as desired from minimum to maximum or vice versa, and that for any of the current modalities illustrated in Figs. 13, 14, 15, 16, 17, 18, 19, 24:, 25, 26 and 27, the rapidity or frequency of the relatively slow sinusoidal current waves may be chan ed as desired through a considerable range, y means of the knob 21. In practice, I find it desirable to rotatethe brushes 70 and 71, slowly relatively to the frequency of alternating current found in ordinary house lighting circuits, which is usually sixty cycles per second, so that the slow sinusoidal current delivered by means of the brushes 7 O and 71 may have as low a frequency as 10 or 12 cycles per minute up to 100 to 125 cycles per minute as desired. My machine thus affords a means for selectively delivering to the patients circuit a large number of current modalities, any one of which may have a large number of different impressed voltages, and any one of which resultin from the operation of the brushes 7 O and 71, or either of them, may be given many different rates or frequencies of slow sinusoidal action. It will also be noted that for any current modality applied to the posts 17 and 18, where the current flow is uni-directional, the current in the patients circuit, may be given either direction of flow desired, by means of the pole changing switch 16.

Circuit connections In Fig. 11, I illustrate diagrammatically the circuit connections of mymachine. In this figure, the main switch M and the auxiliary switch A are illustrated diagrammatically with the main switch M in plan view and the auxiliary switch A in bottom view, so that the contacts in each case are above anything that may be supporting them and in position to be engaged by switch blades resting upon them, the direction of progression of the switch blade positions for the auxiliary switch A being reversed, to facilitate visualizing the simultaneous changing from one position to another, of the two switches.

To facilitate tracing the circuit connections, the following system of numbering of the switch contacts is employed. Each radial row of contacts is designated by an Arabic numeral, there being twenty-two of these rows for each switch. Each circular row of contacts is designated by a small letter, the outermost circular row being designatet a, the next inner circular row 7) etc. For example, the innermost contact for the angular position marked 6 of. the main switch M, is designated Mtid. Thus the circular rows of contacts for the main switch M, range from a to d inclusive, and the circular rows of contacts for the switch A, range from. a to f inclusive.

In Fig. 11, the switch blades are not shown, to avoid confusion in tracing the circuit connections. It will be understood that for any numbered position of the switch blades below referredto, the switch blades 91, 95, 96 and 97 are in line with the contacts of switch M of that radial row and electrically connect any contacts in that radial row on which they may then rest, with any contacts respectively in the diametrically opposite radial row on which their opposite ends may rest; also that the arm 100 of the switch A is at the same time in line with the similarly numbered switch blade position of switch A, to electrically connect any of its contacts that may be in that radial row and also in circular rows (1., b and c, and that the arm 99 is in line with the diametrically opposite radial row of its contacts to electrically connect any of its contacts in said opposite radial row that may also be in circular rows (7, e and f.

In Fig. 11, the supply conductors, correspondingwith the outputconductors of the generator 31, are shown at 110, 111, 112, the wire 110 being the positive outplit-conductor from the direct current side of the generator, the wire 112 being one output conductor from the alternating current side of the generator, and the wire 111 being a common conductor connected with the other direct current output conductor 1 11, and also with the other alternating current output conductor 111".

\Vith the switch blades oi the switches M and A in position No. 1, the following circuit connections are made. Vire 11.0, wire 113, contact M17), contact M127), wire 115, choke coil 114, wire 130, wire 116, rheostat winding 11, wire 117, wire 1.18, contact M220, wire 135, contact Ala, contact A17), wire 138, wi e 143, contact M120, contact M10, wire 119 to wire 111. This impresses direct current from wires 110 and .111 upon the rheostat wind-- ing 11. \Vire 117 is connected by wire 120 with the pole changing switch 116 and the' rheostat arm 90 is connected by wire 121 with the other supply terminal of the pole changing switch 16. One output terminal of the pole changing switch 16 is connected The condenser 151 is at this time connected with the wires 122 and 123 through wire 148, contact M12a, contact Mla, wire 1 17' and wire 119, to cooperate with the choke coil 114, in smoothing out any slight ripples that might otherwise be present in the direct current flow. As a result of these connections, direct or galvanic current as illustrated in Fig. 12, is deliveredto the posts 17 and 18, and thus to the patients circuit.

lVhen the switch blades are moved to position No. 2 the following circuit connections are made. Vire 110, wire 113, contact M271, contact M13a, wire 12 1, wire 125, terminal 88, rotor winding 72, terminal-89, wire 127, wire 128, contact M137), contact M25, wire 119,'t0 wire 111. This causes direct current flow through the rotor/winding 72 resulting in a voltage drop through said winding substaintially equal to the voltage of the generator. At the same time the following connections are made. Rotor brush 71, to collector ring 80, brush 82, wire 126, contact'M2d, contact M13rl, wire 116, rheostat winding 11, wire 1-17, Wire 118, contact M130, contact M20, wire 119 to wire 111. It will be noted that the condenser 151 is not used in this case, and that the circuit connections between the rheostat winding 41 and the posts 17 and 18 remain the same at all times, and that therefore it is unnecessary to trace this part of the circuit in each case. The circuits just traced result in impressing on the terminals of the rheostat winding 41 unidirectional galvanic wave current, as a result of which the current modality illustrated in Fig. 13, is delivered from posts 17 and 18 to the patients circuit.

When the switch blades are moved to position No. 3, the following circuit connections are made. Vire 110, wire 118, contact M3a, contact MM-a, wire 124. wire 125, terminal 88, rotor winding 72", terminal 89, wire 127, wire 128, contact M1 17), contact M37), wire 119, to wire 111, thus causing galvanic current to iiow through the rotor winding 72". In addition, the following circuit connections are made. Rotor brush 70, collector ring 79, brush 81, wire 129. contact M30, contact M140, wire 118, wire 117, rheostat winding 11, wire 116, contact M1417, contact Miid, wire 126, brush 82, collector ring-80, rotor brush 71. The circuit just traced results in supplying slow galvanic sinusoidal current illustrated in Fig. 14, to the rheostat winding 41 and thus to the posts 17 and 18.

When the switch blades are moved to position No. 4, the following circuit connections are made. Wire 111, wire 119, contact M4a, contact M15a, wire 124, wire 125, terminal 88, rotor winding 72", terminal 89, wire 127, wire 128, contact M156, contact M46, to wire 112. This causes alternating current flow through the rotor winding 72". In addition, the followin circuit connections are made. Rotor brush 70, collector ring 7 9, brush 81, wire 129, contact M40, contact M150, wire 118, wire 117, rheostat winding 41, wire 116, contact M1501, contact M4d, wire 126, brush 82, collector ring.80, to rotor brush 71. The circuits Just traced communicate the alternations of the alternating current flowing through the rotor winding 72" to the posts 17 and 18 with sinusoidally varying voltages determ ned by the rotation of the rotor brushes 70 and 71 in the manner above described, resulting in alternating sinusoidal wave current, illustrated in F igv 15, being supplied to the patients circuit.

When the switch blades are moved to posi* tion No. 5, the following circuit connections are made. Wire 110, wire 113, contact M5a, contact M16a, wire 124, wire-125, terminal 88, rotor winding 7 2", terminal 89, wire 127, wire 128, contact M166, contact M56, to wire 112. This supplies a combination of direct or galvanic current and alternating current to the a rotor winding 72". In addition the following circuit connections are made. Rotor brush 71, collector ring 80, brush 82, wire 126,

I contact M511, contact M1601, wire 116, rheostat winding 41, wire 117, wire 118, contact M160, contact M50, wire 129, brush 81, collector ring 79, to rotor brush 7(). This connects the rheostat winding 41 with the rotor brushes 70 and 71, as a result of which superimposed wave current, illustrated in Fig. 16, is supplied to the posts 17 and 18, and to the patients circuit.

When the switch blades are moved to position No. 6, the following circuit connections are made. \Vire 112, contact M66, contact M176, wire 128, wire 127, terminal 89, rotor winding 72", terminal 88, wire 125, contact 44 and 45.

A17d, contact A17e, wire 131, contact M17a, contact M6a, wire 119, to wire 111. In addition, the following circuit connections are made. Plunger contact 44, wire 132, wire 133, contact A6a, contact A66, wire 134 to plunger contact 45. The connections last traced short circuit that part of the rotor winding 72" between the plunger contacts In addition, the following circuit connections are made. Rotor brush 70, collector ring 79, brush 81, wire 129, contact M contact M170, wire 118, wire 117, rheostat winding 41, wire 116, contact MlTd, con tact M6(Z, wire 126, brush 82, collector ring 80, rotor brush 71. The circuits just traced result in impressing upon the rheostat winding 41, and upon the posts 17 and 1S, alternating sinusoidal interrupted current illustrated in Fig. 17, the short circuiting of the mid section of the rotor winding 72" causing an interruption in current flow between successive waves or groups of alternations, and thus producing the current modality illustrated diagrammatically in Fig. 17.

lVhen the switch blades are moved to position No. 7, the following circuit connections are made. Wire 110, wire 113, contact M7a, contact M18a, wire 124, wire 125, terminal 88, rotor winding 72", terminal 89, wire 127, wire 128, contact M186, contact M7 6,.wire 119, to wire 111. In addition to these connections, the mid-section of the retor winding 72" is short circuited as follows: plunger contact 44, wire 132, wire 133, contact A7a, contact A76, wire 134 to plunger contact 45. At the same time the rotor brushes are connected as follows. Rotor brush 70, collector ring 79, brush 81, wire 129, contact M70, contact M180, wire 118, wire 117, rheostat winding 41, wire 116, contact Ml8d, contact M7 d, wire 126, brush 82, collector ring 80, to rotor brush 71. This supplies galvanic current to the rotor winding 72", and the rotor brushes and 71 cause slow galvanic sinusoidal current to flow from the posts 17 and 18 in a manner similar to that described for the current modality shown in Fig. 14, the difference being that for the period during which the rotor brushes 70 and 71 pass over the now short circuited midportion of the rotor winding 72", there is no electrical potential difference between them and an interruption in current flow results between each pair of slow sinusoidal waves of current delivered from the posts 17 and 18, producing in the patients circuit slow sinusoidal interrupted current illustrated in Fig. 18.

\Vhen the switch blades are moved to position No. 8, the following circuit connections are made. Wire 110, wire 113, contact M8a, contact M19a, wire 124, wire 125, terminal 88, rotor winding 72", terminal 89, wire 127, wire 128, contact M196, contact M86, wire 119, to.wire 111. In addition, the following circuit connections are made. Rotor brush 71, collector ring 80, brush 82, wire 126, contact M8d, contact M19d, wire 116, rheostat winding 41, wire 117, wire 118, contact M190, wire 135, contact Ala, wire 136, contact A86, and thence in two paths as follows: first, to contact A8a, wire 140, to wire 111, and second, to contact A80, wire 134, to plunger contact 45. As a result one end portion of the rotor winding 72" is short circuited, and this end is connected with the rheostat winding 41. Thus galvanic current is caused to flow through the remaining portion of said winding, and the electrical potential difference between the supply conductor connected with the short circuited portionof said rotor winding and one of the rotor brushes is impressed upon the rheostat winding 41, and a desired part of it, depending upon the setting of the rheostatarm 90, is impressed upon the posts 17 and 18. Furthermore, when the rotor brush passes over the short circuited end portion of the rotor winding said potential difference is zero and current flow in the patients circuit connected with the posts 17 and 18 is interrupted, and the current modality supplied to the patients circuit is interrupted galvanic wave current illustrated in Fig. 19.

When the switch blades are moved to position No. 9, the following circuit connections are made. Wire 112, contact Mild, contact M20d, wire 116, rheostat winding 41, wire 117, wire 118, contact M200, contact M90, wire 119, to wire 111. This causes alternating or rapid sinusoidal current to flow through the rheostat winding 41, and such a part of itsvoltage to be communicated to the posts 17 and 18 as may be determined by the position of the arm 90 on the rheostat winding, and as a result rapid sinusoidal current illustrated in Fig. 20, is caused to flow in the patients circuit. In this case I illustrate the manner in which the ammeter 23 in the patients cir cuit may be shunted, where, as in this case, the current flow through it is of a kind to which the ammeter, if of the direct current type, cannot respond. As shown, the terminals of the ammeter are connected by wires .150 and 149 with contacts M9a and M20a respectively, and since said contacts are now connected by switch blade 94, a low resistance conductive path for current flow is provided around the ammeter, which prevents current flow to an appreciable extent through the ammeter. Obviously, any available contacts for any of the switch blade positions, that can be connected by any one of the switch blades in that position, may be similarly employed, if desired.

hen the switch blades are moved to position N o. 10, the following circuit connections are made. \Vire 112, contact M10d, contact M21d, wire 116, rheostat winding 41, wire 117, brush 87, rotary interrupter 85, brush 86, wire 137, wire 138, wire 139, contact A106, contact AlOa, wire 140, to wire 111. This has the same effect as above discussed resulting in the current modality illustratedin Fig. 20, excepting that the supply circuit to the rheostat winding 41 is periodically opened, depending upon the rate of rotation of the interrupter 85, thus producing interrupted rapid sinusoidal current, illustrated'in Fig.

21. It will be noted that the interrupter 85 comprises two conducting segments 85 and 85*, the segment 85 being greater than a half circle in angular extent, and thesegmcnt 85 being correspondingly less than a half circle in angular extent, and insulated from the segment 85. As a result of the brushes 86 and 87 being diametrically opposite each other, asabove described, they cannot both engage the segment 85 at the same time, and

the circuit controlled by the interrupter 85, is closed during the periods when both of the brushes engage the segment 85, and is opened by the interrupter during the periods when either of the brushes engages only the segment 85". In this case, the ammeter 23 is shunted by wires 150 and 149 extending from its terminals to cont-acts MlOa and M2111 respectively, which contacts are now connected by switch blade 94, closing a low resistance conductive path around the ammeter.

WVhen the switch blades are moved to position No. 11, the following circuit connections are made. Wire 110, wire 141, contact A116, contact Alla, wire 142, contact Mlld, contact M22al, wire 116, rheostat winding 41, wire 117, wire 1'18, contact M220, contact M110, to wire 112. In this manner a combination of galvanic and alternating or rapid sinusoidal current is supplied to the rheostat winding 41, and combined galvanic and sinusoidal current illustrated in Fig. 22, is delivered to the posts 17 and 18 at a voltage determined by the position of the arm 90 on the rheostat winding 41.

When the switch blades are moved to position No. 12, the following circuit connections are made. Wire 110, wire 113, contact M16, contact M126, wire 115, choke coil 114, wire 180, wire 116, rheostat winding 41, wire 117,

brush 87, interrupter 85, brush 86,-wire 137,

wire 148, contact M120, contact M10, wire 119, to wire 111. In this manner galvanic current is caused to flow through the rheostat winding 41 in the same manner described for the current modality shown in Fig. 12, excepting that in this case the interrupter 85 is included in the circuit and periodically opens and closes the circuit, depending upon the rate of rotation of the interrupter. A desired part of the voltage upon the current flowing through the rheostat winding 41, is impressed upon the posts 17 and 18 to produce in the patients circuit, interrupted galvanic current illustrated in Fig. 23. In this case the condenser 151 is connected with the wires 122 and 123 in the same manner and for a purpose similar to that described above in connection with position No. 1 of the switch blades. It will be noticed that with this current modality, the current flow is substantially constant and maximum throughout the entire duration of each period of current flow, instead of gradually increasipg to its maximum value and then gradually decreasing to ,ZQIO, as is the case for the interrupted galdescribed, is also connected with the adjacent plunger contact and segmental contact as follows: wire 125, contact A-13a to contacts A136 and A130 and from said contacts respectively by wires 144 and 132 to segmental contact 77 and plunger contact 4 1. At the same time, one of the rotor brushes is connected as follows: wire 111, wire 119, contact M20, contact M130, wire 118, wire 117, rheostat winding 11, wire 116, contact M13d, contact M2d, wire 126, brush 82, collector ring 80, to rotor brush 71. The connection described result in producing current flow from the posts 17 and 18 in the patients circuit, similar to the current modality illustrated in Fig. 13, the difference being due to now short-circuiting one end portion of the rotor winding 72?). The connection of the plunger contact 14 with the terminal 88 of the rotor winding 72?), short-circuits that end portion of the winding, but if alone depended upon, would not result in a uniform electrical potential on the rotor brush 71 when it travels over the short-circuited end portion of the winding, due to a slight difference in resistance between the rotor brush and the shortcircuiting connection as the brush passes over the wire of the short-circuitedportion of the winding. To avoid this departure from a uniformly maximum value of the current wave throughout each period of travel of the brush over the short-circuited portion of the rotor winding, at the same time the rotor brush 71 enters the short circuited zone of the rotor winding 72?), the auxiliary brush 74c engages the segmental contact 77 and remains in engagement therewith until the rotor brush 71 leaves the short-circuited Zone, thus providing a path of low resistance between the brush 71 and the terminal 88 and maintaining maximum electrical potential on the brush 71 during each entire period of its travel across the short-circuited zone of the rotor winding 72. This results in supplying to the posts 17 and 18, galvanic wave sus' tained peak current illustrated in Fig. 21.

lVhen the switch blades are moved to position No. 14, the following circuit connections are made. Wire 110, wire 1.13, contact M30, contact Mleta, wire 124, wire 125, terminal 88, rotor winding 7 2?), terminal 89, wire 127, wire 128, contact M146, contact M31), wire 119, to wire 111. This connects the rotor winding 7 2b with the supply wires 110 and 111 in the same manner described above for position No. 3 of the switch blades. In addition, connection is made between wire 125 and contacts A14a, A1 11) and A110, and between the latter two contacts and segmental contact 77 and plunger contact 11 respec tively by wires 144 and 132. This establishes the same short circuited condition of the end portion of the rotor winding 72?), adjacent the terminal 88. as described for position No. 13 of the switch blades. At the same time,

connection is made between wire 127, segmental contact 78 and plunger contact 45, as follows: wire 127, wire 146, contact A3 to contacts A36 and A3cl, and from the latter contacts by wires 145 and 13 1 respectively to segmental contact 78 and plunger contact 45. This short circuits the end portion of the rotor winding 7 26 adjacent the terminal 89 in the same manner and with the same results described for the now short circuited condition of the end portion of the rotor winding 72?) adjacent the terminal 88; At the same time, the rotor brushes and 71 are connected as follows: rotor brush 70, col lector ring 79, brush 81, wire 129, contact M30, contact M140, wire 118, wire 117, rheostat winding 41, wire 116, contact Ml td, contact M3tl, wire 126, brush 82, collector ring 80, to rotor brush 71. This connects the rotor brushes with the rheostat winding 41 in the same manner described above for position No. 3 of the switch blades, but with the difference that the maximum current value through the winding 11, is maintained during each period that the rotor brushes 70 and 71 engage the short-circuited zones of the rotor winding 72?). It is to be noted that the relation of the auxiliary brush 74 to the rotor brush 71 is substantially the same as the relation already described, of the auxiliary brush 7 3 to the rotor brush 70, as a result of which the auxiliary brushes 73 and 74; suc cessively and alternately engage the segmental contacts 77 and 78; it is further to be noted that for each entire period that either of the rotor brushes 70 and 71 is in either of the short-circuited zones of the rotor winding 7 2?), the other of said brushes isin the other of said short-circuited zones. As a result, slow galvanic sinusoidal sustained peak current illustrated in Fig. 25, is supplied to the patients circuit connected with the posts 17 and 18.

When the switch blades are moved to position No. 15, the following circuit connections are made. \Vire 111, wire 119, contact M lo, contact 1115a, wire 124. wire 125, terminal 88, rotor winding 72", terminal 89, wire 127, wire 128, contact M151), contact M15, to wire 112. This supplies alternating current to the rotor winding 72 in the same manner de scribed above for the production of alternating sinusoidal wave current, illustrated in Fig. 15. At the same time the following circuit connections are made. Rotor brush 70, collector ring 79, brush 81, wire 129, contact M10, contact 1115c, wire 118, wire 117, rheostat winding 11, wire 11f, contact M15(Z, contact 114/], wire 126, brush 82, collector ring 80, to rotor brush 71. This connects the rotor brushes 70 and 71 with the rheostat winding 11 in the same manner described above for the current modality illustrated in Fig. 15. At the same time, the following circuit connections are made: wire 125, contact A15a to 1 contacts A15?) and A150 and from the latter contacts by wires 144 and 132 respectively to segmental contact 77 and plunger contact 44; also, from wire 127 wire 146, contact A4f to contacts A46 and A4d and from the latter contacts, by wires 145 and 134 respectively, to segmental contact 78 and plunger contact 45. Thus the terminals 88 and 89 are connected with the segmental contacts 77 and 78 and with the plunger contacts 44 and 45 in the same manner described for the production of slow galvanic sinusoidal sustained peak current illustrated in Fig. 25, the difference in the present case being that alternating current is now supplied to the rotor winding 72", and as a result, alternating sinusoidal sustained peak current illustrated in Fig. 26, is delivered from the posts 17 and 18 to the patients circuit.

With the switch blades moved to position N o. 16, the following circuit connections are made. \Vire 110, wire 113, contact M5a, contact M16a, wire 124, wire 125, terminal 88, rotor winding 72, terminal 89, wire 127, wire 128, contact M16b, contact M5b,to wire 112. This causes combined galvanic and alternating current to flow through the rotor winding 72 in the same manner described above for the production of superimposed wave current illustrated in Fig. 16. At the same time, circuit connections are made as follows: rotor brush 71, collector ring 80, brush 82, wire 126,

ner described above for the current modality illustrated in Fig. 16. At the same time the following circuit connections are made: wire 125, contact A16a, to contacts A16?) and A160 connected by wires 144 and 132 respectively with segmental contact 77 and plunger contact 44-; also wire 127, wire 146, contact A5) to contacts A56 and A5(Z connected by wires 145 and 134 with segmental contact 78 and plunger contact 45. This short circuits the end portions of the rotor winding 72 in the same manner described in connection with the production of slow galvanic sinusoidal sustained peak current illustrated in Fig. 25, the difference being that in the present case, by supplying combined galvanic and alternating current to the rotor winding 72, superimposed wave sustained peak current illustrated in Fig. 27, is delivered from the posts 17 and 18 to the patients circuit.

From the above, it will appear that my improved wave producing mechanism has important characteristics as follows: first, the rotor winding provides a plurality of electrical contact points of progressingly different electrical potential, whereby a brush resting upon one of said contact points is given the same electrical potential to cause current flow in a circuit of which the brush may be a part; second,two series of such contact points are provided, in circular arrangement with points of maximum difference of electrical potential at opposite points of the circle; third, the retation of one or more brushes on said contact points produces a wave of electromotive force between one of the brushes and one of said contact points or between said brushes as the case may be; fourth, by uniformly distributing among said contact points the maximum difference of electrical potential, and equally spacing said contact points in a linear direc tion, and by uniformly rotating said brushes, an electromotive force of true sine wave form is impressed upon the brush or brushes; fifth, with the contact points stationary, it impresses one cycle of electromotive force on the brush or brushes, as the case may be, for each rotation of the brushes, resulting in no great er relative movement between the contact points and the brushes, than the frequency of the slow sinusoidal electromotive force impressed upon the brush or brushes, which is equal to their rate of rotation, insuring accurate and reliable contact between the brushes and the contact points; sixth, it impresses upon the brush or brushes, a resultant electromotive force of slow sinusoidal wave form, whether the electromotive force distributed among the contact points be direct, alternating and of whatever frequency it may be, or of any other form; seventh, by extending a conductor or conductors from a contact point or points of intermediate electrical potential, and connecting the conductor or conductors with the end contact point or points of the series, or by connecting the conductors with each other, the distribution of electrical potential between the contact points is shifted in different ways, permitting the impressing on the output circuit of (a) uni-directional slow wave electromotive force with sustained peak, (5) uni-directional interrupted slow wave electromotive force, (0) slow sinusoidal electromotive force with sustained peak, and (cl) interrupted sinusoidal electromotive force, the particular nature of each electromotive force so impressed, depending upon the nature of the electromotive force distributed among the contact points. Furthermore, all of these conditions may be produced with the brush or brushes rotating at the same uniform rate, and for any of these conditions, the rate of rotation of the brush or brushes may be instantly changed through a considerable range without stopping the machine, or changing any of its parts; eighth, by the use of contact segment or segments and the auxiliary brush orbrushes, and connections selectively made between the segment or segments and the end one or ones of the series of contact points, the short-circuited end zones of the contact points are positively maintained at constant electrical potential lltL throughout the said zones, producing sustained peak waves having peak values that are constant.

While I have shown my invention in the particular embodiment above described, it will be understood that I do not limit myself to this exactconstruction as I may employ equivalents known to the art at the time of the filing of this application without departing from the scope of the appended claims.

What I claim is:

1. In an electro-therapeutic machine, the combination of a flat block of insulating material, a resistance winding having its turns extending in parallel relation across the flat surface of said block, a brush mounted for rotation upon and laterally of the turns of said winding on said fiat surface, means imparting continuous operation to said brush, and devices for selectively maintaining certain turns of said winding within the path of travel of said brush at substantially the same electrical potential.

2. In an electro-therapeutic machine, the combination of a flat block of insulating material, a resistance winding having its turns extending in parallel relation across the flat surface of said block, brushes mounted for rotation upon and laterally of the turns of said winding on said fiat surface, means imparting continuous operation to said brushes, and devices for selectively maintaining certain turns of said winding within the paths of travel of said brushes at substantially the same electrical potential.

3. In an electro-therapeutic machine, the combination of a flat block of insulating ma terial, a resistance winding having its turns extending in parallel relation across the flat surface of said block, brushes mounted for rotation upon and laterally of the turns of said winding on said fiat surface, means imparting continuous operation to said brushes, and devices for selectively maintaining certain turns of said winding within the paths of travel of said brushes at substantially the same electrical potential, the paths of travel of said brushes on said winding being substantially coincident.

4. In an electro-therapeutic machine, the combination of a flat block of insulating material, a resistance winding having its turns extending in parallel relation across the flat surface of said block, a brush mounted for rotation upon and laterally of the turns of said winding on said fiat surface, means imparting continuous operation to said brush, and switching mechanism for selectively short-circuiting certain turns of said winding within the path of travel of said brush.

5. In an electro-therapeutic machine, the combination of a flat block of insulating material, a resistance winding having its turns extending in parallel relation across the flat surface of said block, brushes mounted for rotation upon and laterally of the turns of said winding on said flat surface, means imparting continuous operation to said brushes, and switching mechanism for selectively short-circuiting certain turns of said Winding within the paths of travel of said brushes.

6. In an electro-therapeutic machine, the combination of a fiat block of insulating material, a resistance winding having its turns extending in parallel relation across the flat surface of said block, brushes mounted for rotation upon and laterally of the turns of said winding on said fiat surface, means imparting continuous operation to said brushes, and switching mechanism for selectively short-circuiting certain turns of said winding within the paths of travel of said brushes, the paths of travel of said brushes on said winding being substantially coincident.

7. In an electro-therapeutic machine, means for delivering wave current of low frequency with interruptions between successive waves, comprising the combination of a flat resistance winding for receiving current from a desired source, a brush mounted for rotation upon a fiat side of the turns of said winding, means imparting continuous operation to said brush, electrical connections for selectively short-circuiting turns of said winding adjacent one of its ends and extending into the path of travel of said brush, and delivery circuit connections extending from said' brush and from the shortcircuited end of said winding, whereby for each passage of said brush over said shortcircuited turns there is a corresponding interruption in current flow in the delivery circuit.

8. In an electro-therapeutic machine, means for delivering wave current of low frequency with interruptions between successive waves, comprising the combination of a flat resistance winding for receiving current from a desired source, brushes mounted for rotation upon a flat side of the turns of said winding, means imparting continuous operation to said brushes, electrical connections for selectively short-circuiting turns of said winding at its mid portion in the paths of travel of said brushes, and delivery circuit connect-ions extending from said brushes, whereby for each passage of said brushes over said short-circuited turns there is a corresponding interruption in current flow in the delivery circuit.

9. In an electro-therapeutic machine, means for delivering wave current of low frequency with sustained peak voltage for each wave, comprising the combination of a flat resistance winding for receiving current from a desired source, a brush mounted for rotation upon a fiat side of the turns of said winding, means imparting continuous oper- 

